leon, pci-peripherals: SMP support by spin-locks and updated genirq

8 files changed, 412 insertions, 142 deletions

diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_701.c b/c/src/lib/libbsp/sparc/shared/pci/gr_701.c
index 40a0a2560e..a6c9ebcd5c 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_701.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_701.c
@@ -23,6 +23,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 #include <pci/access.h>
 
@@ -37,6 +38,16 @@
 
 #include <bsp/gr_701.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /* Offset from 0x80000000 (dual bus version) */
 #define AHB1_BASE_ADDR 0x80000000
 #define AHB1_IOAREA_BASE_ADDR 0x80100000
@@ -87,8 +98,9 @@ struct pci_bridge_regs {
 /* Private data structure for driver */
 struct gr701_priv {
 	/* Driver management */
-	struct drvmgr_dev	*dev;
+	struct drvmgr_dev		*dev;
 	char				prefix[16];
+	SPIN_DECLARE(devlock);
 
 	struct pci_bridge_regs		*pcib;
 	struct amba_bridge_regs		*ambab;
@@ -200,7 +212,9 @@ void gr701_interrupt(void *arg)
 	struct gr701_priv *priv = arg;
 	unsigned int status;
 	int irq = 0;
+	SPIN_ISR_IRQFLAGS(irqflags);
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	while ( (status=priv->pcib->istatus) != 0 ) {
 		priv->interrupt_cnt++;	/* An interrupt was generated */
 		irq = status;
@@ -208,6 +222,7 @@ void gr701_interrupt(void *arg)
 		/* ACK interrupt */
 		priv->pcib->istatus = 0;
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller still drives the IRQ. */
 	if ( irq )
@@ -347,6 +362,12 @@ int gr701_init1(struct drvmgr_dev *dev)
 	if ((bar0_size == 0) || (bar1_size == 0))
 		return DRVMGR_ENORES;
 
+	/* Initialize spin-lock for this PCI perihperal device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	priv->genirq = genirq_init(16);
 	if ( priv->genirq == NULL ) {
 		free(priv);
@@ -410,12 +431,17 @@ int ambapp_gr701_int_register(
 	void *arg)
 {
 	struct gr701_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
+
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	status = genirq_register(priv->genirq, irq, h);
 	if ( status == 0 ) {
 		/* Clear IRQ for first registered handler */
 		priv->pcib->iclear = (1<<irq);
@@ -423,7 +449,8 @@ int ambapp_gr701_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -434,7 +461,7 @@ int ambapp_gr701_int_register(
 	} else if ( status == 1 )
 		status = DRVMGR_OK;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -446,10 +473,11 @@ int ambapp_gr701_int_unregister(
 	void *arg)
 {
 	struct gr701_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -457,11 +485,16 @@ int ambapp_gr701_int_unregister(
 		priv->pcib->imask &= ~(1<<irq); /* mask interrupt source */
 	}
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -471,19 +504,19 @@ int ambapp_gr701_int_unmask(
 	int irq)
 {
 	struct gr701_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("GR-701 IRQ %d: enable\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_FAIL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ */
 	priv->pcib->imask |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -493,19 +526,19 @@ int ambapp_gr701_int_mask(
 	int irq)
 {
 	struct gr701_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("GR-701 IRQ %d: disable\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_FAIL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable IRQ */
 	priv->pcib->imask &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_cpci_gr740.c b/c/src/lib/libbsp/sparc/shared/pci/gr_cpci_gr740.c
index 3ba55c5442..7ff7206199 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_cpci_gr740.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_cpci_gr740.c
@@ -33,6 +33,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 
 #include <ambapp.h>
@@ -45,6 +46,16 @@
 
 #include <bsp/gr_cpci_gr740.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /* Determines which PCI address the AHB masters on the GR740 board will
  * access when accessing the AHB to PCI window, it should be set so that the
  * masters can access the HOST RAM.
@@ -98,7 +109,8 @@ struct gr740_grcg_regs {
 struct gr_cpci_gr740_priv {
 	/* Driver management */
 	struct drvmgr_dev	*dev;
-	char			prefix[20];
+	char			prefix[16];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t		pcidev;
@@ -213,10 +225,13 @@ void gr_cpci_gr740_isr(void *arg)
 	struct gr_cpci_gr740_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq, eirq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* DBG("GR-CPCI-GR740: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq = 0; irq < 32; irq++) {
 		if (status & (1 << irq)) {
 			if (irq == priv->eirq) {
@@ -235,6 +250,7 @@ void gr_cpci_gr740_isr(void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller
 	 * still drives the IRQ
@@ -461,11 +477,11 @@ int gr_cpci_gr740_init1(struct drvmgr_dev *dev)
 
 	/* Generate Device prefix */
 
-	strcpy(priv->prefix, "/dev/gr7400");
-	priv->prefix[10] += dev->minor_drv;
+	strcpy(priv->prefix, "/dev/gr740_0");
+	priv->prefix[11] += dev->minor_drv;
 	mkdir(priv->prefix, S_IRWXU | S_IRWXG | S_IRWXO);
-	priv->prefix[11] = '/';
-	priv->prefix[12] = '\0';
+	priv->prefix[12] = '/';
+	priv->prefix[13] = '\0';
 
 	priv->devinfo = devinfo = (struct pci_dev_info *)dev->businfo;
 	priv->pcidev = devinfo->pcidev;
@@ -485,6 +501,12 @@ int gr_cpci_gr740_init1(struct drvmgr_dev *dev)
 	}
 	printf(" IRQ: %d\n\n\n", devinfo->irq);
 
+	/* Initialize spin-lock for this PCI perihperal device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	/* Let user override which PCI address the AHB masters of the
 	 * GR740 board access when doing DMA to HOST RAM. The AHB masters
 	 * access the PCI Window of the AMBA bus, the MSB 2-bits of that address
@@ -576,12 +598,17 @@ int ambapp_gr740_int_register(
 	void *arg)
 {
 	struct gr_cpci_gr740_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if (status == 0) {
 		/* Clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -589,7 +616,8 @@ int ambapp_gr740_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -600,7 +628,7 @@ int ambapp_gr740_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -612,10 +640,11 @@ int ambapp_gr740_int_unregister(
 	void *arg)
 {
 	struct gr_cpci_gr740_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -623,11 +652,16 @@ int ambapp_gr740_int_unregister(
 		priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 	}
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -637,19 +671,19 @@ int ambapp_gr740_int_unmask(
 	int irq)
 {
 	struct gr_cpci_gr740_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("GR740 IRQ %d: unmask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ for first enabled handler only */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -659,19 +693,19 @@ int ambapp_gr740_int_mask(
 	int irq)
 {
 	struct gr_cpci_gr740_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("GR740 IRQ %d: mask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable/mask IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_leon4_n2x.c b/c/src/lib/libbsp/sparc/shared/pci/gr_leon4_n2x.c
index 4a51884b49..cb78de4032 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_leon4_n2x.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_leon4_n2x.c
@@ -32,6 +32,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 
 #include <ambapp.h>
@@ -44,6 +45,16 @@
 
 #include <bsp/gr_leon4_n2x.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /* Determines which PCI address the AHB masters on the LEON-N2X board will
  * access when accessing the AHB to PCI window, it should be set so that the
  * masters can access the HOST RAM.
@@ -98,6 +109,7 @@ struct gr_cpci_leon4_n2x_priv {
 	/* Driver management */
 	struct drvmgr_dev	*dev;
 	char			prefix[20];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t		pcidev;
@@ -213,10 +225,13 @@ void gr_cpci_leon4_n2x_isr(void *arg)
 	struct gr_cpci_leon4_n2x_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq, eirq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* DBG("GR-CPCI-LEON4-N2X: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq = 0; irq < 32; irq++) {
 		if (status & (1 << irq)) {
 			if (irq == priv->eirq) {
@@ -235,6 +250,7 @@ void gr_cpci_leon4_n2x_isr(void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller
 	 * still drives the IRQ
@@ -508,6 +524,12 @@ int gr_cpci_leon4_n2x_init1(struct drvmgr_dev *dev)
 	}
 	printf(" IRQ: %d\n\n\n", devinfo->irq);
 
+	/* Initialize spin-lock for this PCI perihperal device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	/* Let user override which PCI address the AHB masters of the
 	 * LEON4-N2X board access when doing DMA to HOST RAM. The AHB masters
 	 * access the PCI Window of the AMBA bus, the MSB 2-bits of that address
@@ -599,12 +621,17 @@ int ambapp_leon4_n2x_int_register(
 	void *arg)
 {
 	struct gr_cpci_leon4_n2x_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if (status == 0) {
 		/* Clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -612,7 +639,8 @@ int ambapp_leon4_n2x_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -623,7 +651,7 @@ int ambapp_leon4_n2x_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -635,10 +663,11 @@ int ambapp_leon4_n2x_int_unregister(
 	void *arg)
 {
 	struct gr_cpci_leon4_n2x_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -646,11 +675,16 @@ int ambapp_leon4_n2x_int_unregister(
 		priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 	}
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -660,19 +694,19 @@ int ambapp_leon4_n2x_int_unmask(
 	int irq)
 {
 	struct gr_cpci_leon4_n2x_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("LEON4-N2X IRQ %d: unmask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ for first enabled handler only */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -682,19 +716,19 @@ int ambapp_leon4_n2x_int_mask(
 	int irq)
 {
 	struct gr_cpci_leon4_n2x_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("LEON4-N2X IRQ %d: mask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable/mask IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_adcdac.c b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_adcdac.c
index 32891313ff..6d1f8f130f 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_adcdac.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_adcdac.c
@@ -23,6 +23,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 
 #include <ambapp.h>
@@ -35,6 +36,16 @@
 
 #include <bsp/gr_rasta_adcdac.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /*#define DEBUG 1*/
 
 #ifdef DEBUG
@@ -76,8 +87,9 @@ struct gr_rasta_adcdac_ver {
 /* Private data structure for driver */
 struct gr_rasta_adcdac_priv {
 	/* Driver management */
-	struct drvmgr_dev	*dev;
+	struct drvmgr_dev		*dev;
 	char				prefix[20];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t			pcidev;
@@ -193,10 +205,13 @@ void gr_rasta_adcdac_isr (void *arg)
 	struct gr_rasta_adcdac_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* DBG("GR-RASTA-ADCDAC: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq=0; irq<16; irq++) {
 		if ( status & (1<<irq) ) {
 			genirq_doirq(priv->genirq, irq);
@@ -206,6 +221,7 @@ void gr_rasta_adcdac_isr (void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller still drives the IRQ. */
 	if ( tmp )
@@ -411,6 +427,12 @@ int gr_rasta_adcdac_init1(struct drvmgr_dev *dev)
 	if ((bar0_size == 0) || (bar1_size == 0))
 		return DRVMGR_ENORES;
 
+	/* Initialize spin-lock for this PCI perihperal device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	/* Let user override which PCI address the AHB masters of the
 	 * RASTA-ADCDAC board access when doing DMA to CPU RAM. The AHB masters
 	 * access the PCI Window of the AMBA bus, the MSB 4-bits of that address
@@ -488,12 +510,17 @@ int ambapp_rasta_adcdac_int_register(
 	void *arg)
 {
 	struct gr_rasta_adcdac_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if ( status == 0 ) {
 		/* Clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -501,7 +528,8 @@ int ambapp_rasta_adcdac_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -512,7 +540,7 @@ int ambapp_rasta_adcdac_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -524,10 +552,11 @@ int ambapp_rasta_adcdac_int_unregister(
 	void *arg)
 {
 	struct gr_rasta_adcdac_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -535,11 +564,16 @@ int ambapp_rasta_adcdac_int_unregister(
 		priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 	}
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -549,19 +583,19 @@ int ambapp_rasta_adcdac_int_unmask(
 	int irq)
 {
 	struct gr_rasta_adcdac_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-ADCDAC IRQ %d: unmask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ for first enabled handler only */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -571,19 +605,19 @@ int ambapp_rasta_adcdac_int_mask(
 	int irq)
 {
 	struct gr_rasta_adcdac_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-ADCDAC IRQ %d: mask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable/mask IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_io.c b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_io.c
index 95bbee9902..1e424f67f0 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_io.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_io.c
@@ -23,6 +23,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 
 #include <ambapp.h>
@@ -35,6 +36,16 @@
 
 #include <bsp/gr_rasta_io.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /* Determines which PCI address the AHB masters will access, it should be
  * set so that the masters can access the CPU RAM. Default is base of CPU RAM,
  * CPU RAM is mapped 1:1 to PCI space.
@@ -108,8 +119,9 @@ struct gr_rasta_io_ver {
 /* Private data structure for driver */
 struct gr_rasta_io_priv {
 	/* Driver management */
-	struct drvmgr_dev	*dev;
+	struct drvmgr_dev		*dev;
 	char				prefix[16];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t			pcidev;
@@ -233,10 +245,13 @@ void gr_rasta_io_isr (void *arg)
 	struct gr_rasta_io_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* DBG("GR-RASTA-IO: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq=0; irq<16; irq++) {
 		if ( status & (1<<irq) ) {
 			genirq_doirq(priv->genirq, irq);
@@ -246,6 +261,7 @@ void gr_rasta_io_isr (void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller still drives the IRQ. */
 	if ( tmp ) 
@@ -590,6 +606,12 @@ int gr_rasta_io_init1(struct drvmgr_dev *dev)
 	if ((bar0_size == 0) || (bar1_size == 0))
 		return DRVMGR_ENORES;
 
+	/* Initialize spin-lock for this PCI peripheral device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	/* Let user override which PCI address the AHB masters of the
 	 * GR-RASTA-IO board access when doing DMA to CPU RAM. The AHB masters
 	 * access the PCI Window of the AMBA bus, the MSB 4-bits of that address
@@ -685,12 +707,17 @@ int ambapp_rasta_io_int_register(
 	void *arg)
 {
 	struct gr_rasta_io_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if ( status == 0 ) {
 		/* Clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -698,7 +725,8 @@ int ambapp_rasta_io_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -709,7 +737,7 @@ int ambapp_rasta_io_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -721,10 +749,11 @@ int ambapp_rasta_io_int_unregister(
 	void *arg)
 {
 	struct gr_rasta_io_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -732,11 +761,16 @@ int ambapp_rasta_io_int_unregister(
 		priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 	}
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -746,19 +780,19 @@ int ambapp_rasta_io_int_unmask(
 	int irq)
 {
 	struct gr_rasta_io_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-IO IRQ %d: unmask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ for first enabled handler only */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -768,19 +802,19 @@ int ambapp_rasta_io_int_mask(
 	int irq)
 {
 	struct gr_rasta_io_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-IO IRQ %d: mask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable/mask IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_spw_router.c b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_spw_router.c
index 8bce1186ff..7f7e35085a 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_spw_router.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_spw_router.c
@@ -21,6 +21,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 
 #include <ambapp.h>
@@ -32,6 +33,16 @@
 #include <bsp/genirq.h>
 #include <bsp/gr_rasta_spw_router.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /* Determines which PCI address the AHB masters will access, it should be
  * set so that the masters can access the CPU RAM. Default is base of CPU RAM,
  * CPU RAM is mapped 1:1 to PCI space.
@@ -93,6 +104,7 @@ struct gr_rasta_spw_router_priv {
 	/* Driver management */
 	struct drvmgr_dev	*dev;
 	char			prefix[20];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t		pcidev;
@@ -209,10 +221,13 @@ void gr_rasta_spw_router_isr(void *arg)
 	struct gr_rasta_spw_router_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* DBG("GR-RASTA-SPW-ROUTER: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq=0; irq<16; irq++) {
 		if ( status & (1<<irq) ) {
 			genirq_doirq(priv->genirq, irq);
@@ -222,6 +237,7 @@ void gr_rasta_spw_router_isr(void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller
 	 * still drives the IRQ
@@ -423,6 +439,12 @@ int gr_rasta_spw_router_init1(struct drvmgr_dev *dev)
 	if (bar0_size == 0)
 		return DRVMGR_ENORES;
 
+	/* Initialize spin-lock for this PCI peripheral device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	/* Let user override which PCI address the AHB masters of the
 	 * GR-RASTA-SPW board access when doing DMA to CPU RAM. The AHB masters
 	 * access the PCI Window of the AMBA bus, the MSB 4-bits of that address
@@ -495,12 +517,17 @@ int ambapp_rasta_spw_router_int_register(
 	void *arg)
 {
 	struct gr_rasta_spw_router_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if (status == 0) {
 		/* Clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -508,7 +535,8 @@ int ambapp_rasta_spw_router_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -519,7 +547,7 @@ int ambapp_rasta_spw_router_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -531,10 +559,11 @@ int ambapp_rasta_spw_router_int_unregister(
 	void *arg)
 {
 	struct gr_rasta_spw_router_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -542,11 +571,16 @@ int ambapp_rasta_spw_router_int_unregister(
 		priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 	}
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -556,19 +590,19 @@ int ambapp_rasta_spw_router_int_unmask(
 	int irq)
 {
 	struct gr_rasta_spw_router_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-SPW-ROUTER IRQ %d: unmask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ for first enabled handler only */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -578,19 +612,19 @@ int ambapp_rasta_spw_router_int_mask(
 	int irq)
 {
 	struct gr_rasta_spw_router_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-SPW-ROUTER IRQ %d: mask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable/mask IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_tmtc.c b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_tmtc.c
index c8ba4c4962..6ca3c6be1a 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_tmtc.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_rasta_tmtc.c
@@ -23,6 +23,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 
 #include <ambapp.h>
@@ -35,6 +36,16 @@
 
 #include <bsp/gr_rasta_tmtc.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
 /* Determines which PCI address the AHB masters will access, it should be
  * set so that the masters can access the CPU RAM. Default is base of CPU RAM,
  * CPU RAM is mapped 1:1 to PCI space.
@@ -104,8 +115,9 @@ struct gr_rasta_tmtc_ver {
 /* Private data structure for driver */
 struct gr_rasta_tmtc_priv {
 	/* Driver management */
-	struct drvmgr_dev	*dev;
+	struct drvmgr_dev		*dev;
 	char				prefix[20];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t			pcidev;
@@ -224,10 +236,13 @@ void gr_rasta_tmtc_isr (void *arg)
 	struct gr_rasta_tmtc_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* printk("GR-RASTA-TMTC: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq=0; irq<32; irq++) {
 		if ( status & (1<<irq) ) {
 			genirq_doirq(priv->genirq, irq);
@@ -237,6 +252,7 @@ void gr_rasta_tmtc_isr (void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller still drives the IRQ. */
 	if ( tmp )
@@ -602,6 +618,12 @@ int gr_rasta_tmtc_init1(struct drvmgr_dev *dev)
 	if ((bar0_size == 0) || (bar1_size == 0))
 		return DRVMGR_ENORES;
 
+	/* Initialize spin-lock for this PCI peripheral device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	/* Let user override which PCI address the AHB masters of the
 	 * GR-RASTA-TMTC board access when doing DMA to CPU RAM. The AHB masters
 	 * access the PCI Window of the AMBA bus, the MSB 4-bits of that address
@@ -689,12 +711,17 @@ int ambapp_rasta_tmtc_int_register(
 	void *arg)
 {
 	struct gr_rasta_tmtc_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if ( status == 0 ) {
 		/* Disable and clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -702,7 +729,8 @@ int ambapp_rasta_tmtc_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -713,7 +741,7 @@ int ambapp_rasta_tmtc_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -725,10 +753,11 @@ int ambapp_rasta_tmtc_int_unregister(
 	void *arg)
 {
 	struct gr_rasta_tmtc_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -737,11 +766,16 @@ int ambapp_rasta_tmtc_int_unregister(
 	} else if ( status == 1 )
 		status = 0;
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -751,19 +785,19 @@ int ambapp_rasta_tmtc_int_unmask(
 	int irq)
 {
 	struct gr_rasta_tmtc_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-TMTC IRQ %d: unmask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -773,19 +807,19 @@ int ambapp_rasta_tmtc_int_mask(
 	int irq)
 {
 	struct gr_rasta_tmtc_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("RASTA-TMTC IRQ %d: mask\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_EINVAL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
diff --git a/c/src/lib/libbsp/sparc/shared/pci/gr_tmtc_1553.c b/c/src/lib/libbsp/sparc/shared/pci/gr_tmtc_1553.c
index d56d8d7652..ec51ec312d 100644
--- a/c/src/lib/libbsp/sparc/shared/pci/gr_tmtc_1553.c
+++ b/c/src/lib/libbsp/sparc/shared/pci/gr_tmtc_1553.c
@@ -23,6 +23,7 @@
 
 #include <bsp.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/isrlock.h> /* spin-lock */
 #include <pci.h>
 #include <pci/access.h>
 
@@ -36,6 +37,15 @@
 
 #include <bsp/gr_tmtc_1553.h>
 
+/* map via rtems_interrupt_lock_* API: */
+#define SPIN_DECLARE(lock) RTEMS_INTERRUPT_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) rtems_interrupt_lock_initialize(lock, name)
+#define SPIN_LOCK(lock, level) rtems_interrupt_lock_acquire_isr(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) rtems_interrupt_lock_acquire(lock, &level)
+#define SPIN_UNLOCK(lock, level) rtems_interrupt_lock_release_isr(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) rtems_interrupt_lock_release(lock, &level)
+#define SPIN_IRQFLAGS(k) rtems_interrupt_lock_context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
 
 /*#define DEBUG 1 */
 
@@ -60,8 +70,9 @@ struct gr_tmtc_1553_ver {
 /* Private data structure for driver */
 struct gr_tmtc_1553_priv {
 	/* Driver management */
-	struct drvmgr_dev	*dev;
+	struct drvmgr_dev		*dev;
 	char				prefix[32];
+	SPIN_DECLARE(devlock);
 
 	/* PCI */
 	pci_dev_t			pcidev;
@@ -174,10 +185,13 @@ void gr_tmtc_1553_isr (void *arg)
 	struct gr_tmtc_1553_priv *priv = arg;
 	unsigned int status, tmp;
 	int irq;
+	SPIN_ISR_IRQFLAGS(irqflags);
+
 	tmp = status = priv->irq->ipend;
 
 	/* DBG("GR-RASTA-IO: IRQ 0x%x\n",status); */
 
+	SPIN_LOCK(&priv->devlock, irqflags);
 	for(irq=0; irq<16; irq++) {
 		if ( status & (1<<irq) ) {
 			genirq_doirq(priv->genirq, irq);
@@ -187,6 +201,7 @@ void gr_tmtc_1553_isr (void *arg)
 				break;
 		}
 	}
+	SPIN_UNLOCK(&priv->devlock, irqflags);
 
 	/* ACK interrupt, this is because PCI is Level, so the IRQ Controller still drives the IRQ. */
 	if ( tmp ) 
@@ -306,11 +321,11 @@ int gr_tmtc_1553_init1(struct drvmgr_dev *dev)
 
 	/* Generate Device prefix */
 
-	strcpy(priv->prefix, "/dev/tmtc1553_0/");
-	priv->prefix[19] += dev->minor_drv;
+	strcpy(priv->prefix, "/dev/tmtc1553_0");
+	priv->prefix[14] += dev->minor_drv;
 	mkdir(priv->prefix, S_IRWXU | S_IRWXG | S_IRWXO);
-	priv->prefix[20] = '/';
-	priv->prefix[21] = '\0';
+	priv->prefix[15] = '/';
+	priv->prefix[16] = '\0';
 
 	priv->devinfo = devinfo = (struct pci_dev_info *)dev->businfo;
 	priv->pcidev = devinfo->pcidev;
@@ -328,6 +343,12 @@ int gr_tmtc_1553_init1(struct drvmgr_dev *dev)
 	if (bar0_size == 0)
 		return DRVMGR_ENORES;
 
+	/* Initialize spin-lock for this PCI peripheral device. This is to
+	 * protect the Interrupt Controller Registers. The genirq layer is
+         * protecting its own internals and ISR dispatching.
+         */
+	SPIN_INIT(&priv->devlock, priv->prefix);
+
 	priv->genirq = genirq_init(16);
 	if ( priv->genirq == NULL ) {
 		free(priv);
@@ -394,12 +415,17 @@ int ambapp_tmtc_1553_int_register(
 	void *arg)
 {
 	struct gr_tmtc_1553_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *h;
 
-	rtems_interrupt_disable(level);
+	h = genirq_alloc_handler(handler, arg);
+	if ( h == NULL )
+		return DRVMGR_FAIL;
 
-	status = genirq_register(priv->genirq, irq, handler, arg);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
+
+	status = genirq_register(priv->genirq, irq, h);
 	if ( status == 0 ) {
 		/* Disable and clear IRQ for first registered handler */
 		priv->irq->iclear = (1<<irq);
@@ -408,7 +434,8 @@ int ambapp_tmtc_1553_int_register(
 		status = 0;
 
 	if (status != 0) {
-		rtems_interrupt_enable(level);
+		SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
+		genirq_free_handler(h);
 		return DRVMGR_FAIL;
 	}
 
@@ -419,7 +446,7 @@ int ambapp_tmtc_1553_int_register(
 	} else if ( status == 1 )
 		status = 0;
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return status;
 }
@@ -431,10 +458,11 @@ int ambapp_tmtc_1553_int_unregister(
 	void *arg)
 {
 	struct gr_tmtc_1553_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 	int status;
+	void *handler;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	status = genirq_disable(priv->genirq, irq, isr, arg);
 	if ( status == 0 ) {
@@ -443,11 +471,16 @@ int ambapp_tmtc_1553_int_unregister(
 	} else if ( status == 1 )
 		status = 0;
 
-	status = genirq_unregister(priv->genirq, irq, isr, arg);
-	if ( status != 0 )
+	handler = genirq_unregister(priv->genirq, irq, isr, arg);
+	if ( handler == NULL )
 		status = DRVMGR_FAIL;
+	else
+		status = DRVMGR_OK;
+
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
-	rtems_interrupt_enable(level);
+	if (handler)
+		genirq_free_handler(handler);
 
 	return status;
 }
@@ -457,19 +490,19 @@ int ambapp_tmtc_1553_int_unmask(
 	int irq)
 {
 	struct gr_tmtc_1553_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("TMTC-1553 IRQ %d: enable\n", irq);
 	
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_FAIL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Enable IRQ */
 	priv->irq->mask[0] |= (1<<irq); /* unmask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }
@@ -479,19 +512,19 @@ int ambapp_tmtc_1553_int_mask(
 	int irq)
 {
 	struct gr_tmtc_1553_priv *priv = dev->parent->dev->priv;
-	rtems_interrupt_level level;
+	SPIN_IRQFLAGS(irqflags);
 
 	DBG("TMTC-1553 IRQ %d: disable\n", irq);
 
 	if ( genirq_check(priv->genirq, irq) )
 		return DRVMGR_FAIL;
 
-	rtems_interrupt_disable(level);
+	SPIN_LOCK_IRQ(&priv->devlock, irqflags);
 
 	/* Disable IRQ */
 	priv->irq->mask[0] &= ~(1<<irq); /* mask interrupt source */
 
-	rtems_interrupt_enable(level);
+	SPIN_UNLOCK_IRQ(&priv->devlock, irqflags);
 
 	return DRVMGR_OK;
 }